* {
  user-select: none;
}
#game {
  position: relative;
  height: 600px;
  width: 100%;
  background: url(../images/sky.png);
  background-position-x: 0px;
  overflow: hidden;
}
#game .bird {
  position: absolute;
  left: 50%;
  top: 235px;
  margin-left: -15px;
  width: 30px;
  height: 30px;
  background: url(../images/birds.png);
  transition: top 0.3s linear;
}
#game .start {
  position: absolute;
  top: 295px;
  left: 50%;
  margin-left: -100px;
  width: 200px;
  height: 60px;
  line-height: 60px;
  text-align: center;
  font-weight: bolder;
  cursor: pointer;
  transition: all 0.3s linear;
}
#game .start.start-white {
  color: #fff;
  font-size: 24px;
}
#game .start.start-blue {
  color: #09f;
  font-size: 36px;
}
#game .score {
  position: absolute;
  left: 50%;
  top: 50px;
  transform: translateX(-50%);
  font-size: 20px;
  font-weight: bolder;
  color: #fff;
  display: none;
  z-index: 2;
}
#game .mask {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  opacity: 0.7;
  background: #000;
  display: none;
  z-index: 2;
}
#game .end {
  position: absolute;
  left: 50%;
  top: 70px;
  transform: translateX(-50%);
  text-align: center;
  display: none;
  z-index: 2;
}
#game .end .over {
  font-size: 30px;
  font-weight: bolder;
  color: red;
}
#game .end .result,
#game .end .final-score {
  margin-top: 20px;
  color: #ff0;
  font-size: 20px;
  font-weight: bold;
}
#game .rank-list {
  color: #09f;
  margin-top: 20px;
}
#game .rank-list .rank-item {
  height: 30px;
  line-height: 30px;
  margin-bottom: 10px;
  font-size: 14px;
}
#game .rank-list .rank-item .rank-degree {
  width: 14px;
  height: 14px;
  color: #fff;
  background: #8eb9f5;
  display: inline-block;
  line-height: 14px;
  font-size: 12px;
  margin-right: 10px;
}
#game .rank-list .rank-item .rank-degree.first {
  background: #f54545;
}
#game .rank-list .rank-item .rank-degree.second {
  background: #ff8547;
}
#game .rank-list .rank-item .rank-degree.third {
  background: #ffac38;
}
#game .rank-list .rank-item .rank-score {
  width: 30px;
  display: inline-block;
}
#game .restart {
  color: #09f;
  font-size: 18px;
  font-weight: bolder;
  cursor: pointer;
}
#game .pipe {
  position: absolute;
  width: 52px;
}
#game .pipe.pipe-up {
  top: 0;
  background: url(../images/pipe2.png) center bottom;
}
#game .pipe.pipe-down {
  background: url(../images/pipe1.png) center top;
  bottom: 0;
}
